Ketil Bjørnstad returns to the piano/cello duo, instrumentation which defined two of his best-loved albums, “The River” and “Epigraphs” with David Darling, back in 1996 and 1998. This new collaboration with Svante Henryson, however, tells a different story. As cellist, Henryson currently works in duos and trios with distinguished classical musicians including pianists Roland Pöntinen and Bengt Forsberg, clarinettist Martin Fröst, mezzo-soprano Anne Sofie von Otter and baritone Mikael Samuelson. ECM listeners, however, first heard him as a member of Jon Balke’s Magnetic North Orchestra on “Kyanos” (2001). In jazz contexts, he has also played in diverse formations with Tord Gustavsen, Marilyn Mazur, Nils Petter Molvaer, Arild Andersen and others. In rock and pop, he has collaborated with artists from Yngwie Malmsteen to Elvis Costello. In brief, he is an artistic polymath, rather like composer/improviser/author Bjørnstad himself. The music they create together - atmospheric, dark-hued, of melancholic temperament - is similarly beyond category.